147results about How to "Loss in efficiency" patented technology

An electroluminescent (EL) device including an illumination area having one or more primary EL emitters; a reference area having a reference EL emitter; a reference driver circuit for causing the reference EL emitter to emit light while the EL device is active; a sensor for detecting light emitted by the reference EL emitter; and a measurement unit for detecting an aging-related electrical parameter of the reference EL emitter while it is emitting light. The device further includes a controller for receiving an input signal for each primary EL emitter in the illumination area, forming a corrected input signal from each input signal using the detected light and the aging-related electrical parameter, and applying the corrected input signals to the respective primary EL emitters in the illumination area.

An annular circulation chamber is arranged in an interior of a compressor housing, which circulation chamber radially surrounds a main flow duct and extends from an intake region to an encircling circulation opening in a region of rotor blades of the compressor wheel. Between the circulation openings, the circulation chamber is delimited from the main flow duct by an annular contoured wall. The contoured wall is connected to the inner compressor housing by plural struts which are spaced apart from one another to different extents in the circumferential direction. As a result of the irregular distribution of the struts in the circumferential direction, generation of undesired vibration excitations can be reduced and / or eliminated.

A converter control device comprises: a voltage-zero-cross detection unit detecting zero cross of the alternate-current voltage and outputting a voltage zero-cross signal; a power-source-current detection unit detecting a power source current of the alternate-current power source; a bus-line-voltage detection unit detecting a bus-line voltage between terminals of the smoothing capacitor; a PWM-signal generation unit generating a PWM-signal for on / off-controlling the switching unit, based on the power-source current, the bus-line voltage and a bus-line-voltage command value as a target voltage of the bus-line voltage; a power-source voltage-state detection unit detecting a signal state of the alternate-current voltage based on the voltage zero-cross signal; and a fundamental-switching-frequency selection unit selecting a fundamental switching frequency of the PWM-signal based on the signal state of the alternate-current voltage. The PWM-signal generation unit generates the PWM-signal based on a fundamental switching signal having a fundamental switching frequency selected by the fundamental-switching-frequency selection unit.

A motor drive apparatus and motor drive method reduce vibration and acoustic noise by not requiring a non-activation period for rotor position detection, and enable stable, high efficiency motor drive. A control voltage generator generates a control voltage based on the frequency of the speed signal FG output from a speed detection unit, and the amplitude of the control voltage is controlled based on a torque control signal EC. The phase difference generator detects the phase difference between the control voltage and the zero cross signal of the motor current detected from the motor terminal voltages. A control voltage generator controls the phase of the control voltage so that the phase difference goes to zero, thus accomplishing sensor-less motor drive.